The quaternary lithostratigraphy aspects of the Wallachian Depression (Romania)

The Pliocene and Quaternary continental lithostratigraphy from the Wallachian Depression (situated between the South Carpathians and the Balkans) in Romania, named the Bucharest Group can be subbdivided into (progressively subsiding west to east from northeastward of the Romanian Plain): 1-Dacian Subgroup, characterized by the Dacian Area (Environment), predominantly alluvial plain, unconsolidated marshland, drained by the Dacian River Network (terrace free); 2-Wallachian Subgroup, characterized by the Wallachian Area (Environment), consolided dry ground, drained by the Wallachian River Network (straight and terraced water courses); 3-Cândeşti Subgroup, characterized by the Cândeşti Area (alluvial fan-Environment); 4-Danube Delta Subgroup, characterized by the Danube Delta Area (delta environment). The Dacian Subgroup can be divided into two formations: Danube-Siret Formation, Wallachian-Lower Pleistocene in the west of the Romanian Plain (Bălăciţa – Olt Member: detritic dominance) and the Wallachian – Lower Holocene in the east of the Romanian Plain (Titu – Măicăneşti Member: pelitic dominance.). The Wallachian Subgroup can be divided into four formations: 1-Drincea-Olt Formation (red ferruginous clays, weathering crust), at the limit between the Lower Pleistocene and Middle Pleistocene; 2-Craiova-Galaţi Formation (predominant aeolian loess deposits), Middle Pleistocene-Upper Pleistocene); 3-Romanian Plain Formation (Complex), terrace and floodplain deposits of the Wallachian River Network valleys, Middle Pleistocene-Holocene; 4-Calafat Formation, Holocene, aeolian sandy dunes. The evolution of the Danube itself marked two periods: 1-Paleofluvial Period (Lower Pleistocene, presumably beginning in the Upper Pontian), when the Dacian Danube did already exist (a modest river, flowing in the Dacian River Network at its entrance into the Romanian Plain) and the Pannonian Danube (Danubes) also a rather modest rivers which flowed into the Dacian River Network at its entrance into the Pannonian Plain; 2-Neofluvial Period, Middle Pleistocene-Actual, when the Pannonian-Dacian (Actual) Danube already exist and was part of the Wallachian River Network formed in the lower part of the Middle Pleistocene, right after being caught in the Defile which had facilitated the formation of very important lively river. The Danube reached Galaţi (and the Black Sea) after the Siret and the Prut River dit it, during the upper part of the Upper Pleistocene. The Danube Channel, the Danube Canyon, yhe Danube Deep-Sea Fan, the Paleo-Danube presumably represent the Siret (including the Prut) Channel, the Siret Canyon.